Recognition of conspecifics by honeybee guards uses nonheritable cues acquired in the adult stage

Abstract

Social insects use both environmental and heritable (genetic) recognition cues when discriminating between nestmates and non-nestmates. In honeybees, Apis mellifera, both types of recognition cues are used, although their relative importance depends upon context, experimental design and environmental factors. Our aim in this study was to investigate which cues honeybees use to discriminate between nestmates and non-nestmates under natural conditions. To do this, we used an assay of nestmate recognition that very closely simulated natural conditions, with naturally occurring guards at actual nest entrances and workers that had been naturally reared and had spent their adult life in a hive. Guards exclusively used environmental recognition cues when encountering entering bees. There was no evidence that guards used heritable cues: related nestmates and unrelated nestmates, unrelated non-nestmates and related non-nestmates all had the same probability of being accepted (ca. 80 versus 20%). Possible reasons why heritable cues are not used are discussed.